Many modem communication systems allow for inter-link operation communications and maintenance commands between the coupled communication devices by the utilization of message packets passed over the communication link on a limited bandwidth embedded operations channel (EOC). The EOC is incorporated into the transfer protocol. One recent such communications link and protocol is the high-speed digital subscriber line (HDSL), also known as the high-bit-rate digital subscriber line (HDSL), which has 2 wire and 4 wire variants (HDSL2 and HDSL4). The HDSL2 and HDSL4 protocols are defined in industry standards (ANSI T1E1.418) to provide for common conventions and interoperability between HDSL communication devices from differing manufacturers. In particular, the EOC message packets allow configuration and management of such communication devices as the central office (CO) HDSL communication device and the customer premise equipment (CPE)/remote (RMT) HDSL communication device by the remote operation of their configuration menus across the HDSL communication link through the EOC channel embedded within the HDSL protocol and framing. In managing and configuring an HDSL communication device across an HDSL communication link, a technician or system operator connects to a local HDSL device with a terminal device or interface device. The system operator then utilizes the terminal device and local HDSL device to connect to the remote HDSL communication device being configured through the EOC channel of the HDSL communication link. Once connected the system operator generally utilizes a menu generated by a configuration application running on the distant HDSL communication device to manage and configure the device. Typically the interface device or terminal device utilized by the system operator to interface with the local HDSL communication device is a text or ASCII terminal. Other terminal types, such as a graphics user interface (GUI), are known and utilized for this purpose.
A common problem in communicating across the EOC channel occurs when there are errors in transmission of the EOC data/frame of the communication link, also known as EOC channel blocking. The EOC data packet portion of the datastream is corrupted, and thus when it is received the frame check sequence (FCS) of the EOC packet is checked against the contents of the packet and the packet is discarded because of the corruption. A corrupt EOC packet that has been discarded is typically not resent and is therefore lost. This loss of inter-link operation communications and maintenance commands can cause major problems in the overall operation of the communication link and the coupled communication devices. In particular, this is a problem for system operators engaged in remotely managing and/or configuring a distant communication device over the EOC channel; the corrupted EOC packets are discarded by the receiving communication device and therefore the high end applications or the system operator's terminal device they are destined for never receives them. This can lead to many issues such as corrupted screens and menus on the system operator's terminal, failed status updates, and misconfigurations of the distant communication device due to dropped packets.
An additional problem is the typically limited resources of the communication devices. Communication devices typically will utilize an embedded processor and memory system with a size and throughput that is closely matched to the needs of operating the communication device in a real time manner to reduce overall costs and power requirements of the system. Therefore, there is generally not an excess of spare resources available to devote to dealing with generating the configuration menu, communicating over the EOC channel, and operating a complex EOC channel error correction system in addition to the normal requirements of maintaining and operating a communication link.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a method and apparatus for conveniently detecting and correcting for EOC packet transmission errors in communication devices and, in particular, HDSL communication devices.